在实验1基础上，
定义一个异常类ScoreException，当输入的学生成绩不在[0,100]区间时，抛出该异常。
定义一个异常类StudentNumberException，当输入的学号不满足下述条件，则抛出该异常。条件为：学号为10位，第1位为2，第2位为0，其余位为数字0~9.
对Student和StudentTest类进行必要修改，提升程序的健壮性。(On the basis of Experiment 1,
An exception class ScoreException is defined, and the exception is thrown when the input student's score is not in the [0100] interval.
An exception class StudentNumberException is defined, and the exception is thrown when the input school number does not satisfy the following condition. Conditions are: 10, first, 2, second, 0, and the rest number 0~9.
The necessary modifications are made to the Student and StudentTest classes to improve the robustness of the program.)